Downsized mutualisms: Consequences of seed dispersers’ body-size reduction for early plant recruitment

Termites are social cockroaches. Because non-termite cockroaches are larger than basal termite lineages, which themselves include large termite species, it has been proposed that termites experienced a unidirectional body size reduction since they evolved eusociality. However, the validity of this hypothesis remains untested in a phylogenetic framework. Here, we reconstructed termite body size evolution using head width measurements of 1638 modern and fossil termite species. We found that the unidirectional body size reduction model was only supported by analyses excluding fossil species. Analyses including fossil species suggested that body size diversified along with speciation events and estimated that the size of the common ancestor of modern termites was comparable to that of modern species. Our analyses further revealed that body size variability among species, but not body size reduction, is associated with features attributed to advanced termite societies. Our results suggest that miniaturization took place at the origin of termites, while subsequent complexification of termite societies did not lead to further body size reduction.

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Frugivore-fruit size relationships between palms and mammals reveal past and future defaunation impacts

Nature Communications ◽

10.1038/s41467-020-18530-5 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Jun Ying Lim ◽

Jens-Christian Svenning ◽

Bastian Göldel ◽

Søren Faurby ◽

W. Daniel Kissling

Keyword(s):

Body Size ◽

Fruit Size ◽

Global Scale ◽

Occurrence Data ◽

Evolutionary Changes ◽

Palm Species ◽

Seed Dispersers ◽

Frugivore Assemblages ◽

The Impact ◽

Old World Tropics

Abstract Mammalian frugivores are critical seed dispersers, but many are under threat of extinction. Futhermore, the impact of past and future defaunation on plant assemblages has yet to be quantified at the global scale. Here, we integrate palm and mammalian frugivore trait and occurrence data and reveal a global positive relationship between fruit size and frugivore body size. Global variation in fruit size is better explained by present-day frugivore assemblages than by Late Pleistocene assemblages, suggesting ecological and evolutionary reorganization after end-Pleistocene extinctions, except in the Neotropics, where some large-fruited palm species may have outlived their main seed dispersers by thousands of years. Our simulations of frugivore extinction over the next 100 years suggest that the impact of defaunation will be highest in the Old World tropics, and an up to 4% assemblage-level decrease in fruit size would be required to maintain the global body size–fruit size relationship. Overall, our results suggest that while some palm species may be able to keep pace with future defaunation through evolutionary changes in fruit size, large-fruited species may be especially vulnerable to continued defaunation.

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Comparative size evolution of marine clades from the Late Permian through Middle Triassic

Paleobiology ◽

10.1017/pab.2015.36 ◽

2015 ◽

Vol 42 (1) ◽

pp. 127-142 ◽

Cited By ~ 21

Author(s):

Ellen K. Schaal ◽

Matthew E. Clapham ◽

Brianna L. Rego ◽

Steve C. Wang ◽

Jonathan L. Payne

Keyword(s):

Body Size ◽

Middle Triassic ◽

Size Reduction ◽

Late Triassic ◽

Early Triassic ◽

Large Species ◽

Late Permian ◽

Triassic Boundary ◽

Median Size ◽

Permian Extinction

AbstractThe small size of Early Triassic marine organisms has important implications for the ecological and environmental pressures operating during and after the end-Permian mass extinction. However, this “Lilliput Effect” has only been documented quantitatively in a few invertebrate clades. Moreover, the discovery of Early Triassic gastropod specimens larger than any previously known has called the extent and duration of the Early Triassic size reduction into question. Here, we document and compare Permian-Triassic body size trends globally in eight marine clades (gastropods, bivalves, calcitic and phosphatic brachiopods, ammonoids, ostracods, conodonts, and foraminiferans). Our database contains maximum size measurements for 11,224 specimens and 2,743 species spanning the Late Permian through the Middle to Late Triassic. The Permian/Triassic boundary (PTB) shows more size reduction among species than any other interval. For most higher taxa, maximum and median size among species decreased dramatically from the latest Permian (Changhsingian) to the earliest Triassic (Induan), and then increased during Olenekian (late Early Triassic) and Anisian (early Middle Triassic) time. During the Induan, the only higher taxon much larger than its long-term mean size was the ammonoids; they increased significantly in median size across the PTB, a response perhaps related to their comparatively rapid diversity recovery after the end-Permian extinction. The loss of large species in multiple clades across the PTB resulted from both selective extinction of larger species and evolution of surviving lineages toward smaller sizes. The within-lineage component of size decrease suggests that only part of the size decrease can be related to the end-Permian kill mechanism; in addition, Early Triassic environmental conditions or ecological pressures must have continued to favor small body size as well. After the end-Permian extinction, size decrease occurred across ecologically and physiologically disparate clades, but this size reduction was limited to the first part of the Early Triassic (Induan). Nektonic habitat or physiological buffering capacity may explain the contrast of Early Triassic size increase and diversification in ammonoids versus size reduction and slow recovery in benthic clades.

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Relative Magnitudes of Crown Size Reduction and Body Size Reduction in 47-Trisomy G

Journal of Dental Research ◽

10.1177/00220345710500027601 ◽

1971 ◽

Vol 50 (2) ◽

pp. 513-513 ◽

Cited By ~ 6

Author(s):

Stanley M. Garn ◽

M. Michael Cohen ◽

John C. Gall ◽

Jerrold Nagy

Keyword(s):

Body Size ◽

Size Reduction ◽

Crown Size

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Influence of faeces on seed removal from gibbon droppings in a dipterocarp forest in Central Borneo

Journal of Tropical Ecology ◽

10.1017/s0266467404001968 ◽

2005 ◽

Vol 21 (1) ◽

pp. 117-120 ◽

Cited By ~ 15

Author(s):

Kim R. McConkey

Keyword(s):

East Asian ◽

Seed Removal ◽

Plant Recruitment ◽

Neotropical Forests ◽

Seed Predators ◽

Dipterocarp Forest ◽

Seed Dispersers ◽

Seed Shadows

Many frugivorous animals disperse seeds in their faeces (Corlett 1998, van der Pijl 1982), which may enhance the ability of secondary seed dispersers and post-dispersal seed predators to locate seeds (Andresen 2001, Chapman 1989, Feer 1999, Janzen 1982). By destroying and moving seeds these animals can radically alter the primary seed shadows generated by frugivorous animals and, consequently, have the potential to influence plant recruitment (Alcántara et al. 2000, Crawley 1992). Nevertheless, the influence of faeces on seed removal in South-East Asian forests has not previously been investigated and our knowledge currently comes from studies in Neotropical forests (Andresen 2001, Chapman 1989, Feer 1999, Janzen 1982).

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Body size reduction under starvation, and the point of no return, in ephyrae of the moon jellyfish Aurelia aurita

Marine Ecology Progress Series ◽

10.3354/meps10799 ◽

2014 ◽

Vol 510 ◽

pp. 255-263 ◽

Cited By ~ 19

Author(s):

Z Fu ◽

M Shibata ◽

R Makabe ◽

H Ikeda ◽

S Uye

Keyword(s):

Body Size ◽

Size Reduction ◽

Aurelia Aurita ◽

The Moon ◽

Moon Jellyfish ◽

Point Of No Return

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The history of body size evolution in termites

10.1101/2021.09.30.462579 ◽

2021 ◽

Author(s):

Nobuaki Mizumoto ◽

Thomas Bourguignon

Keyword(s):

Body Size ◽

Size Reduction ◽

Head Width ◽

Termite Species ◽

Fossil Species ◽

Modern Species ◽

Size Evolution ◽

History Of ◽

Body Size Evolution ◽

Width Measurements

Termites are social cockroaches. Because non-termite cockroaches are larger than basal termite lineages, which themselves include large termite species, it has been proposed that termites experienced a unidirectional body size reduction since they evolved eusociality. However, the validity of this hypothesis remains untested in a phylogenetic framework. Here, we reconstructed termite body size evolution using head width measurements of 1638 modern and fossil termite species. We found that the unidirectional body size reduction model was only supported by analyses excluding fossil species. Analyses including fossil species suggested that body size diversified along with speciation events and estimated that the size of the common ancestor of modern termites was comparable to that of modern species. Our analyses further revealed that body size variability among species, but not body size reduction, is associated with features attributed to advanced termite societies. Our results suggest that miniaturization took place at the origin of termites, while subsequent complexification of termite societies did not lead to further body size reduction.

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Small size does not restrain frugivory and seed dispersal across the evolutionary radiation of Galápagos lava lizards

Current Zoology ◽

10.1093/cz/zoy066 ◽

2018 ◽

Vol 65 (4) ◽

pp. 353-361 ◽

Cited By ~ 2

Author(s):

Sandra HervÍas-Parejo ◽

Ruben Heleno ◽

Beatriz Rumeu ◽

Beatriz Guzmán ◽

Pablo Vargas ◽

...

Keyword(s):

Body Size ◽

Structural Damage ◽

Energy Content ◽

Seedling Emergence ◽

Fruit Size ◽

Head Size ◽

Emergence Time ◽

Fruit Consumption ◽

Fruit Abundance ◽

Seed Dispersers

AbstractFrugivory in lizards is often assumed to be constrained by body size; only large individuals are considered capable of consuming fruits, with the potential of acting as seed dispersers. However, only one previous study has tested the correlation of frugivory with body and head size at an archipelago scale across closely related species. All nine lava lizards (Microlophus spp.) were studied on the eleven largest Galápagos islands from 2010 to 2016 to investigate whether frugivory is related to body and head size. We also tested whether fruit abundance influences fruit consumption and explored the effect of seed ingestion on seedling emergence time and percentage. Our results showed that across islands, lava lizards varied considerably in size (64–102 mm in mean snout–vent length) and level of frugivory (1–23%, i.e., percentage of droppings with seeds). However, level of frugivory was only weakly affected by size as fruit consumption was also common among small lizards. Lava lizards consumed fruits throughout the year and factors other than fruit abundance may be more important drivers of fruit selection (e.g., fruit size, energy content of pulp). From 2,530 droppings, 1,714 seeds of at least 61 plant species were identified, 76% of the species being native to the Galápagos. Most seeds (91%) showed no external structural damage. Seedling emergence time (44 versus 118 days) and percentage (20% versus 12%) were enhanced for lizard-ingested seeds compared to control (uningested) fruits. De-pulping by lizards (i.e., removal of pulp with potential germination inhibitors) might increase the chances that at least some seeds find suitable recruitment conditions. We concluded that lizards are important seed dispersers throughout the year and across the whole archipelago, regardless of body size.

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